1. Field of the Invention
The present invention is related to systems, software, and methods of monitoring equipment and, more particularly, systems software and methods related to cyclic equipment.
2. Discussion of Related Art
Over the years, it has becomes increasingly difficult to evaluate to establish the proper time interval for scheduling preventive maintenance on process equipment. Also, many systems describe what to do when equipment needs maintenance, but few systems actually provide ways to detect deteriorating equipment. Various approaches of evaluating when to schedule maintenance or replacement of the process equipment have prevailed such as using experience with the specific type of equipment, prior practices of others, the users best guess, the manufacturer's recommendations, or to simply do nothing and repair the equipment when it breaks-down. This latter approach is based on an outdated hypothesis which states that it is better to operate equipment until it fails than to accept the maintenance and penalty costs of shutting down prematurely. Other approaches have weighed the cost of premature overhaul of the equipment against the cost of continuing operation and risking unexpected early failure. An even more recent approach has been toward using normal statistical distribution models with data processed by computer programs to determine when to perform scheduled maintenance. Using these normal statistical distribution models and other similar statistical methodologies, it is possible to predict the probability of an “average” piece of equipment failing prior to, on, or after a certain time such that preventive maintenance can be performed prior to probable equipment failure. Statistically, however, many individual pieces of equipment will survive for a longer period but are overhauled prematurely because this methodology and various other statistical methods apply to populations of the same type of equipment and do not actually examine each individual piece of equipment.
An example of this type of system is a conveyor displacing its load only when there is enough weight accumulated on the conveyor and runs until the load gets to a lower weight (See Prior Art FIG. 1). The conveyor is activated by the scale until the weight goes down to a predetermined lower weight. Another example of this type of system is a pump starting only when there is enough liquid accumulated in a tank or a well and runs until a lower level is reached, as seen in lift stations (See Prior Art FIG. 1B). Yet Another example of this type of system is a pump used to fill up a water tower or a tank (See Prior Art FIG. 1C). When the water pressure or level gets to a low point, a pump is activated until the water tower is filled up to a higher pressure or a higher level.
Even more recently, a trend has been toward foregoing statistical methodologies in favor of measuring various equipment parameters of the individual piece of equipment. Most systems made to detect abnormal equipment behaviours use one to many sensors of different type related to the equipment being monitored to supply processed data into usable maintenance information. For example, U.S. Pat. No. 4,707,796, by Calabro et al., titled “Reliability and Maintainability Indicator” describes an attempt to predict the remaining time of operation of a piece of equipment before it would fail by measuring key parameters of the equipment monitored with applicable transducers over time which are correlated and analyzed by a micro-processor based computer.
For many systems, the information supplied must be compared to other information from the same source or other sources to evaluate the deterioration of the equipment being monitored. For example, U.S. Pat. No. 6,308,138B1, by Jones et al., titled “Diagnostic Rule Based Tool Condition Monitoring System” describes a system to monitor various characteristics of the power consumption of a tool and diagnoses the condition of the tool based upon the various characteristics with respect to a Rule base developed from an examination of the same characteristics of a tool of known condition. In U.S. Pat. No. 6,442,511B1, by Sarangapani et al., titled “Method and Apparatus for Determining the Severity of a Trend toward an Impending Machine Failure and Responding to the Same” describes determining a failure trend based on a set of normal operating conditions for the machine by determining the slope value for the typical failure trend and slope value for the trend toward the impending machine failure based on a weighted value of various sensed machine parameters. Also for example, U.S. Pat. No. 6,411,908, by Talbott, titled “Condition-Based Prognosis for Machinery” describes a method for estimating the remaining life in an operating machine that uses condition-based data histories of same-type machines situated in same-type operational environments that have all failed according to the same failure mode, whereby the data is obtained from end-users who have monitored their machines with the appropriate sensor technology and have performed autopsies on the failed machines to verify the failure mode of the machines.
In other systems, like for most flow related systems, the user must further evaluate the data to extract maintenance information like for most known flow related systems. For example, U.S. Pat. No. 5,991,707, by Searies et al., titled “Method and System for Predictive Diagnosing of System Reliability Problems And/or System Failures in a Physical System” describes an attempt to diagnose system reliability problems or system failure through identification of errant fluctuations in one or more operating parameters of a physical system. A datastream of parameter values are divided into one or more sets and the sets are associated into one or more sensors to examine statistically for conditions that indicate whether or not the values are within operating range. Many systems describe what to do when equipment needs maintenance. Only few systems actually provide ways to detect deteriorating equipment.
Applicants have recognized that equipment made to operate at a constant speed on a constant workload often deteriorates as a function of a single variable, namely time. It becomes difficult to evaluate the speed of deterioration with a perpetual variable workload and equipment operating cyclically to displace the accumulated workload. Usually, metering equipment for level, flow, pressure, current, or vibration are added to a process to evaluate the efficiency or speed of deterioration on equipment within the process. Sometimes, the operator must supply operating parameters such as regime, weight or volume to calculate a meaningful value that may indicate the performance of the equipment. If the metering equipment is defective or the operator's input is inaccurate, then the evaluation would be meaningless.
Applicants advantageously have recognized a need to evaluate the efficiency of equipment operating cyclically to displace a variable workload without any input from an operator or the use of sensors or specialized metering equipment.